In recent years, home robots such as robot pets have been vigorously developed, and it is expected that in the future, more practical home robots, such as housekeeping support robots, will be put into practical use. Since home robots are required to enter homes and coexist with people, they need specifications different from those of conventional industrial robots and the like.
In the industrial robots, electric motors and reduction gears are used, and a high-gain feedback control is carried out so that high hand positional precision with a repetition precision of 0.1 mm or the like has been achieved. However, these mechanisms driven by electric motors have high stiffness and tend to lack flexibility, resulting in issues from the viewpoint of safety.
In contrast, the home robots do not necessarily require such high precision with a repetition precision of 0.1 mm or the like, and more emphasis is put on safety to provide characteristics such as being not harmful even upon contact with a human being. Consequently, the mechanisms to be driven by electric motors, such as conventional industrial robots, are not considered to be suitable for the field of home robots and the like on which more emphasis is put on safety, and there has been strong demand for flexible, safe driving mechanisms.
In order to achieve these issues, a driving mechanism to be driven by McKibben type pneumatic actuators has been proposed as a conventional technique. In JP No. 7-27411B (Patent Document 1), a driving apparatus has been proposed in which, by inputting disturbance signals having the same phase to a pneumatic actuator driving circuit, a dithering effect is obtained so that controlling characteristics are improved, and upon detection of an abnormal state in servo components by using a servo valve driving signal or the like, the power source is cut off and brakes of the driving apparatus are operated to prevent an out-of-control state.    Patent Document 1: JP No. 7-27411B